In the prior art, there has been developed a type of implement commonly referred to as a "thumb", mountable on the underside of the handle of an excavating machine which is cooperable with the bucket of the machine for grasping material being handled between the thumb and the bucket. Typically, the thumb is fixed relative to the handle and the bucket may be curled and uncurled to grasp and hold the material being handled. The thumb also is usually connected to the handle with a strut which may be either of a fixed or extendable length to permit adjustment of the angle of the thumb relative to the handle. The strut may consist of rigid link detachably securable to one of a number of brackets deposed on the underside of the handle or a hydraulic cylinder whose length may be varied and locked to position the thumb at the desired angle.
Utilizing a hydraulic cylinder for adjusting the angle of the thumb has a number of advantages but is comparatively costly. Utilizing a rigid strut and a number of connecting brackets also has a number of advantages but presents a number of disadvantages including increased cost of manufacture and installation and a certain amount manual labor being required in fixing the desired angle of the thumb and securing it into position. It thus has been the principal object of the present invention to provide a material handling assembly of the type described having a thumb component which is simple in construction, comparatively easy to install and readily adjustable. It is a further object of the invention to provide such an implement which may be easily set at a desired angle for operational purposes and conveniently retracted and positioned against the underside of the handle for storage purposes, permitting the bucket of the assembly to be operated independently of the thumb member.